The present invention relates to an implantable access port assembly which includes am attachable catheter. The present invention further relates to an access port usable with em attachable catheter that may be inserted into a patient as a unit using a guidewire, the unit having an entry site for a guidewire.
An access port connected to a catheter is used to provide an easily accessible site by which fluids can be easily introduced into or extracted from a remote site in a patient. To place an access port and catheter, a catheter is introduced into a vein, artery, existing lumen, created lumen or into other locations in the patient. A guidewire may first be used to facilitate the positioning of the catheter in the patient. Whether a guidewire is used to place the catheter depends on the characteristics of the catheter, the patient's anatomy at the access point, any constrictions in the catheter's pathway and the like. Where a guidewire is used to help position the catheter, it is first inserted into the patient and advanced to the intended location. Once the guidewire is in place, the catheter is threaded on and positioned over the guidewire in the desired location and the guidewire removed, an access port is then attached to the catheter and inserted into a "surgical pocket" in the patient at the access site. The attachment of the access port to the catheter can, however, be difficult due to the lubricious nature of the catheter and access port during insertion. Additionally, the physician does not have much maneuverability with the catheter since the distal end of the catheter has been placed at a specific location and the proximal end of the catheter has been cut to a length that optimizes placement of the catheter and access port into the surgical pocket. Therefore, the physician must be careful in manipulating the catheter when attaching the access port.
Additionally, there is a concern that the catheters may become detached from the access port after implantation, causing the fluids not to reach their intended location. Integral ports and catheters have not been used where s guidewire is required to place the catheter since the proximal end of the catheter/access port is closed, thereby preventing withdrawal of the guidewire once the catheter is in place.
Access ports used are usually constructed with a rigid-body such as shown in U.S. Pat. No. 5,613,945. The access ports are made of materials such as titanium, acetal, polysulfone, etc., and have a self-sealing silicone access septum that is accessible percutaneously and through which a needle is inserted to inject or remove fluids from the access port's reservoir. An access port must first be located by palpating the skin at the access site. While a rigid-body access port is easy to find by palpation, a rigid-body has possible drawbacks such as tissue compression and erosion in the overlying layer, discomfort, and the like. The access septum is small relative to the size of access port. However, a smaller access septum results in a higher concentration of needle punctures in a smaller area, which in turn could be painful for the patient and may lead to necrosis of the tissue overlying the access port as well. The smaller access septum also increases the likelihood that the septum "target" will be missed more frequently when attempting to access the septum.
One known soft-bodied access port is made of silicone formed around a wire-mesh support to help it maintain its shape. One problem with this structure is that the wire mesh could interfere with the insertion of a guidewire.